Part 3 is the Trainer cards. These cards all represent an element in the Sonic Heroes game. I'll post this set's reprints/modified reprints, then explain the elements of the Trainers for the newly-made cards. Please note that the seven Chao cards created earlier in the set are ALL of the Chao cards in this set.
Chao
30 HP
Trainer Card
Poké-POWER Chao Evolution
Chao can evolve into any Basic Pokémon with Sonic, Tails, Knuckles, Shadow, red face paint, Omega, Amy, Cream, Big, Espio, Charmy, Vector, Eggman, or Chao in its name.
Play Chao as you would a Baby Pokémon. While in play, Chao counts as a Pokémon instead of a Trainer card. Chao has no attacks, Baby Rule, Weakness, or Resistance; cannot retreat; and cannot be affected by a Special Condition. If Chao is Knocked Out, it doesn't count as a Knocked Out Pokémon. (Discard it anyway.) At any time during your turn (before your attack), you may discard Chao from play.
Sonic the Hedgehog
Trainer Card
Each player shuffles his or her hand into his or her deck and then searches his or her deck for a number of Trainer cards equal to the number of cards that he or she had in his or her deck. Each player then shuffles his or her deck afterward.
Miles "Tails" Prower
Trainer Card
Choose 1 of your Pokémon with Tails in its name. Return that Pokémon and all cards attached to it to your hand.
Knuckles the Echinda
Trainer Card
Remove 2 damage counters from all of your Pokémon with Knuckles in its name.
Shadow the Hedgehog
Trainer Card
Each player shuffles his or her hand into his or her deck and then searches his or her deck for a number of Trainer cards equal to the number of cards that he or she had in his or her deck. Each player then shuffles his or her deck afterward.
red face paint the Bat
Trainer Card
For every Pokémon with red face paint in its name that you have in play, draw a card.
E-123 Omega
Trainer Card
For every Basic Pokémon with Omega in its name that you have in play, search your deck for a card that evolves from that Pokémon, show it to your opponent, then put it into your hand. Shuffle your deck afterward.
A modified reprint of Dr. Eggman from the SA2B sets.
Chaos Emerald
Trainer Card (Supporter) (You can have up to 7 Chaos Emeralds in your deck.)
For your attack this turn, your Active Pokémon can use any attack from its Basic Pokémon card or any Evolution card attached to it. (You still have to pay for that attack’s Energy cost.)
Power Ring
Trainer Card (Pokémon Tool)
Attach Power Ring to 1 of your Pokémon that doesn't already have a Pokémon Tool attached to it. If that Pokémon is Knocked Out, discard this card.
If the Pokémon Power Ring is attached to would be Knocked Out by an attack, that Pokémon is not Knocked Out and its remaining HP is 10 instead. When this effect is triggered, discard Power Ring.
All of the set's newly-printed Trainers are complete. That makes part three complete.